A multi-scale framework to predict damage initiation at martensite/ferrite interface

Martensite/ferrite (M/F) interface damage largely controls failure of dual-phase (DP) steels. In order to predict the and assess ductility DP steels, accurate models for M/F interfacial zones are needed. Several have been proposed in literature, which however do not incorporate underlying microphysics. It has recently suggested that (lath) martensite substructure boundary sliding dominates initiation therefore should be taken into account. Considering computationally infeasibility direct numerical simulations statistically representative steel microstructures, while explicitly resolving microstructures activity, a novel multi-scale approach is developed this work. Two scales considered: mesostructure consisting multiple lath islands embedded ferrite matrix, microscopic zone unit cell substructure. Based on emerging pattern, an effective indicator determined from microstructural response, along with cell. Relating these two quantities different configurations leads mesoscale model relating activity island terms mesoscopic kinematics. This microphysics-based model, could envisioned a-priori, fully identified set simulations, thus enabling efficient prediction at mesoscale. The capability demonstrated example realistic mesostructure.